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What is an LED Light Tube?

R. Kayne
R. Kayne

An LED light tube resembles a fluorescent light tube externally and can be used in fluorescent light fixtures, but is made up of a series of LED lights housed within a flexible, non-breakable tube. LED tubes are an energy-saving replacement alternative to traditional fluorescent lights. A Light Emitting Diode (LED) is a low-power, solid-state light that is particularly long lasting and generates very little heat. LED tubes and LED bulbs might be poised to take over where incandescent, fluorescent and compact fluorescent lights (CFLs) left off, barring one or two hurdles. To appreciate LED light technology, first briefly consider traditional bulbs and tubes.

The traditional incandescent light bulb has remained largely unchanged since its invention in 1879 by Thomas Edison. Electricity causes a filament to become so hot that it glows white, producing light. It is extremely affordable to buy, but about 90% of the energy it consumes is wasted by generating heat rather than light, making it expensive to run and a large contributor to the environmental footprint. A 60-watt bulb has a life of 800-1500 hours.

In 1879, Thomas Edison patented his incandescent bulb.
In 1879, Thomas Edison patented his incandescent bulb.

Fluorescent lights use a different method to generate light. Electricity excites atoms of mercury vapor trapped inside a glass light tube. As the excited atoms fall back to a less-excited state, they emit photons of ultra-violet light which are invisible to the human eye. The energy of these photons is absorbed by the phosphor coating on the inside of the light tube, causing it to glow in the visible light spectrum. This design is four to six times more energy-efficient because it does not waste power generating heat; thus a 15-watt fluorescent tube can produce as much light output as a 60-watt incandescent bulb. Fluorescent tube life is rated between 7,000-12,000 hours, depending on the type.

A direct descendant of fluorescent technology is the CFL bulb — the spiral-shaped light reminiscent of a swirled ice-cream cone — which is basically a fluorescent tube morphed into a light bulb with slightly improved technology. It too uses mercury vapors, a coated phosphorus tube, and in this case an integrated ballast for shooting electricity through the tube. A CFL bulb is rated at about 10,000 hours, with a 20-watt CFL producing the same amount of light as a 75-watt incandescent.

A drawback of fluorescent lights and CFL is the toxic mercury vapor they contain, though burning coal also releases mercury vapor into the environment. These bulbs save the environment of the extra mercury that would be produced by coal-burning power plants supplying power to incandescent bulbs in their place. So while they are environmentally better and save money in energy costs, they are not ideal and need to be recycled rather than thrown in the trash. A broken bulb also presents a potential health hazard if handled improperly.

Enter LED technology. LED lights use solid state lighting technology, or a semiconductor as the framework for producing excited electrons responsible for generating light. The semiconductor, typically made of aluminum-gallium-arsenide “doped” with N-Type and P-Type materials – essentially negatively and positively charged materials – relies on electrons changing orbital bands to generate light. An electrical charge is introduced via electrodes connected to either end of the semiconductor, which triggers the orbital changes necessary for the electrons to emit photons in the visible light spectrum.

Several small LED lights are clustered together in a bulb or LED light tube, creating a bright light that uses even less energy than fluorescent or CFL, and lasts longer. An LED light tube is rated up to 50,000 hours and is “instant-on” technology with no annoying flicker.

LED tubes require replacing only once every 10 years or more under normal use, and can use existing fluorescent light fixtures to draw the meager power they consume. Before installing an LED light tube, the starter and ballast must be removed from the fixture, requiring rudimentary re-wiring. The LED light tube might come with directions on how to perform this re-wiring, and guides are also available online. A professional electrician can also be called upon, if preferred.

LED lights are not only more efficient, they don’t contain mercury, making them "greener" and safer. However, it’s pricey up front to switch to LED lighting, even though savings in energy bills not only offsets this, but saves the consumer money over the long run. Also, the light spectrum of LED light might not meet everyone’s expectations, and lights might also be offered in more than once spectrum, such as warm, neutral or cool white, making it difficult for consumers to know which spectrum they will find pleasing.

LED light tubes are available online and might be available at local home improvement stores. Local retailers might also have an LED light display.

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    • In 1879, Thomas Edison patented his incandescent bulb.
      By: nickolae
      In 1879, Thomas Edison patented his incandescent bulb.